The embodiments described herein relate generally to electrical power distribution systems and, more specifically, to managing electricity demand.
In many regions of the world, demand for electricity is nearing electricity generation and delivery capacity. If current capacity remains the same and demand continues to rise, demand will exceed capacity. Generation and delivery capacity depends on both the amount of electricity an electrical utility is able to generate and the amount of electricity the electrical grid connecting the utility to the end users is able to deliver. If demand exceeds capacity, one result may be rolling black-outs where neighborhoods do not receive electricity during peak times of day. Another potential result is rolling brown-outs, where neighborhoods receive lower voltages, which may potentially cause damage to appliances and other equipment.
The rising demand for electricity can be satisfied by increasing electricity generation capacity by constructing new power plants which could include wind, nuclear, solar, gas, and/or coal generation technologies. To deliver the increased electricity generated, the capacity of the electrical grid may also need to be increased. Such construction is expensive and time consuming. Environmental concerns and energy price volatility are also constraints on merely adding conventional power generation facilities to meet the increasing demand.
Businesses and home owners may also install green technologies such as solar cells to generate their own electricity locally and decrease the strain on the grid. However, the upfront costs for these solutions are high, preventing widespread implementation.
Reducing demand during peak hours is another way to prevent demand for electricity from surpassing electricity generation and delivery capacity. Electricity consumption varies throughout a typical day. However, each day the electricity demand curve of electricity consumption varies in a similar manner. For example, during peak times (i.e., morning to early evening), demand for electricity is highest. Demand for electricity is significantly lower early in the morning and late at night. Power storage devices may be charged during non-peak times of the day, which increases the demand during those times of day. The power that is stored can then be used during times of peak demand. This flattens the electricity demand curve by creating a constant demand below capacity limits. However, the cost of current battery technology capable of charging to this high of an energy level is prohibitive.
Demand for electricity at peak times may be passively reduced by an electric utility by increasing the cost of electricity during peak hours. Higher energy costs may motivate customers to reduce electricity usage. This passive solution requires cooperation of the end user as well as action by the end user to remove electrical loads from the grid during peak hours. Some solutions currently exist, such as programmable thermostats, that automatically reduce usage of a high power-usage load during peak hours. Such solutions typically are very limited in the types of devices they control. Demand for electricity may also be actively reduced by an electric utility by taking action to remove electrical loads. For example, a “smart grid” allows a utility to send a signal instructing a “smart device” at a customer location to turn itself off. Typically, equipment used by electric utilities to automatically shed loads from the electric grid requires costly installation at a customer location, many times, requiring the expertise of an electrician.